Unseeded Indian Sania Mirza stormed into the semi-finals of Pattaya Open, overpowering sixth-seeded Tamarine Tanasugarn of Thailand 7-5, 6-4 in Bangkok on Friday.
Sania beat world No.41 Tamarine in an hour and 45 minutes to set-up a semi-final clash with eighth seed Magdalena Rybarikova of Slovakia, who upset second seed Caroline Wozniacki of Denmark 6-4, 6-1.
This will be Sania's first singles semi-final appearance since her return to the international circuit last month after a wrist surgery. Sania won the Australia Open mixed-doubles partnering compatriot Mahesh Bhupathi.
Sania, whose ranking has fallen to 126 as she was out of the circuit with the injury for most part of 2007, had earlier got the better of Tamarine here in 2006. With the victory she improved the overall head-to-head record with the Thai to 2-1.
Sania had an early control of the first set with a break of serve in the sixth game when she led 4-2. Tamarine, however, fought her way back to win three games in a row to nose ahead 5-4. The Indian then stepped up her game to take the next three games.
In the evenly fought second set, Sania converted two break points to Tamarine's one to win the match.